[Johnny555]

Worse, melting land-ice increases sea level, while melting sea ice does not.

If the entire Antarctic ice shelf melted, global sea levels would rise about 60 meters (200 feet).

http://science.howstuffworks.com/environmental/earth/geophys...

Though it would take a huge temperature rise for that to happen -- enough that the other climatic effects would probably be as bad or worse than the sea level rise.

Greenland is not nearly so cold, so it's more likely that its ice shelf would melt, which would add about 7 meters (20 feet) to sea level.

[tempestn]

The larger problem with melting sea ice, as I understand it, is that the reflectivity of water is much lower than that of ice, so less of the incoming energy from the sun is reflected, accelerating warming.